Investigating the effects of tabs geometry and current collectors thickness of lithium-ion battery with electrochemical-thermal simulation

摘要

Lithium-ion batteries, which perform based on the migration of lithium-ion between positive and negative electrodes, are used as a new and rechargeable energy source in electric and hybrid electric vehicles. Lithium-ion batteries should be designed to enhance the performance, lifespan, and durability of the battery. It should also prevent the risk of the thermal runaway and battery explosion at high discharge rates. In this article, a prismatic single-cell of lithium-ion battery is simulated with three-dimensional computational fluid dynamics during discharge cycles at different rates using the electrochemical-thermal method. First, numerical simulation results are validated with experimental results. Then, the results of the state of charge, the electrical potential distribution, the lithium-ion concentration in electrodes and electrolyte, the temperature distribution and the heat generation rate during the discharge cycles at different rates are presented. Finally, by modifying the geometry of the battery and the location of the positive and negative tabs, it has been tried to improve the uniformity of battery parameters such as the lithium-ion concentration and the state of charge and to reduce the maximum battery surface temperature. In the improved geometry, it was observed that the total heat generation rate and the maximum temperature of the battery surface decreased by 19.94 and 2.12 K, respectively. Also, the uniformity in the temperature distribution increased by 47.3 compared to the original geometry of the battery. This will increase the lifespan of the battery and it can also prevent the risk of the thermal runaway at high discharge rates.